Heel safety binding for a ski

ABSTRACT

A heel safety binding for a ski in which a pressure member extending transversely downwardly toward the front of the ski presses upon the rear edge of the heel of the ski boot or a metal heel fitting under a resilient prestress or tension and, upon attaining admissible maximum load, executes an upward angular movement against the prestress in the vertical longitudinal plane of the ski and during which movement the heel is released from the pressure member after a predetermined point in the upward path of movement. More particularly, the pressure member is connected at its upper portion with the upper leg of a substantially C-shaped leaf spring, the closed end of which faces the rear of the ski and the lower leg of which is mounted on a baseplate attached to the ski or directly to the ski.

United States Patent HEEL SAFETY BINDING FOR A SKI 10 Claims, 5 DrawingFigs.

U.S. Cl 280/11-35 T Int. Cl A63c 9/08 Field of Search 280111.35 T

[56] References Cited UNITED STATES PATENTS 2,823,922 2/1958 Berlenbach280/11.35 T 3,379,447 4/1968 Webster 280/1135 T 3,467,407 9/1969 Unger280/1135 T Primary Examiner- Leo Friaglia Assistant ExaminerRobert R.Song Attorney-Holman & Stern ABSTRACT: A heel safety binding for a skiin which a pressure member extending transversely downwardly toward thefront of the ski presses upon the rear edge of the heel of the ski bootor a metal heel fitting under a resilient prestress or tension and, uponattaining admissible maximum load, executes an upward angular movementagainst the prestress in the vertical longitudinal plane of the ski andduring which movement the heel is released from the pressure memberafter a predetermined point in the upward path of movement. Moreparticularly, the pressure member is connected at its upper portion withthe upper leg of a substantially C-shaped leaf spring, the closed end ofwhich faces the rear of the ski and the lower leg of which is mounted ona baseplate attached to the ski or directly to the ski.

lllllllllllllliilf BACKGROUND OF THE INVENTION This invention relates toa heel safety binding for a ski provided with a pressure memberextending transversely downwardly toward the front of the ski underresilient prestress and which member presses upon the rear edge of theheel of the ski boot or a metal fitting at the heel and which, uponreaching a permissible maximum load performs an upward angular movementin the vertical longitudinal plane of the ski against the prestress andduring which angular movement the heel of the ski boot will be releasedfrom the pressure member after a certain upward path of movement.

In a known binding of this general type, the transverse downwardlyforwardly extending pressure member is guided at its front end by aguide means, which per se, is swingably located in a support positionedin the vertical longitudinal median plane of the ski, with the supportextending upwardly from a baseplate mounted on the ski. The resilientprestress which urges the pressure member against a metal fitting at therear of the heel of the ski boot is effected by a set of springsanchored at the bottom of the baseplate and which at the top engages aselector lever located approximately in the middle of the guide meansand which lever from such position extends or projects upwardly. Theselector lever is swingable in the same plane as the guide means and thepressure member, namely between a front final position in which theplane of the lines of application of the springs which engage theselected lever lies forwardly of the joint means connecting the selectorlever with the guide means, and a rear final position in which suchplane lies rearwardly of or behind the joint means. The front finalposition of the selector lever is the downhill skiing position in whichthe torsional moment of the tensions of the spring is high as regardsthe guide means and also in regard to the force with which the pressuremember presses against the metal fitting of the heel. Upon attaining thepermissible maximum load, the selector lever changes to its rear finalposition and in such position, the known binding allows a considerablemovement of the boot heel in an upward direction and therefore issuitable for climbing or cross-country skiing. If, however, even in thisposition of the selector lever the maximum load is reached, the pressuremember swings so far upwardly against the resistance of an additionalspring which grips the pressure member that the metal fitting of theheel is released.

ln another known binding of this character, one forwardly extending legof an angle lever constitutes the pressure member and such lever isswingable about a horizontal axis extending transversely to thelongitudinal direction of the ski. The second leg of the angle lever istubular and includes a piston as well as a spring which is supported bya threaded plug or stopper at the upper end of the tubular leg and whichpresses the piston against a flattened portion of the swinging axis. Thetorsional moment of the spring as regards the swinging axis of the anglelever and also the force with which the pressure member presses againstthe heel of the boot is dependent upon the breadth of the flattenedportion with a given prestress of the spring. ln order that theflattened portion may be sufficiently wide, the diameters of theswinging axis and of the piston must be relatively large and thediameter of the tubular leg of the angle lever is correspondinglylarger.

The two above-mentioned known bindings have proven satisfactory inpractice but do have a considerable height if arranged in such a manneras to be capable of absorbing a certain impact for safety of the skierfor which a considerable extent of flexibility of the spring must beavailable until the ski boot is released from the downhill skiingposition. Moreover, the cost of production of the above two bindings isconsiderable and in connection with the first-described binding this isdue to the number of components and in the second because of therequired precision of the components constituting the binding. Thiscost, however is justified in the first-mentioned binding since it ispossible to utilize the binding also for cross country skiing which isseldom done by a large number of skiers.

SUMMARY OF THE INVENTION The present invention is predicated on theproblem of providing a particularly simple and lightweight heel safetyski binding which is insensitive to wear for downhill skiing and theproblem has been solved by a binding in which the pressure member at itsupper end is connected with the upper leg of a substantially C-shapedleaf spring connected via its lower leg to a baseplate or to the ski perse and which spring is closed towards the rear end of the ski.

The present leaf spring is advantageous as compared to the known guidearrangements in that it is quite resistant against lateral forces evenwhen only of slight thickness with these lateral forces beingtransferred from the heel of the boot to the ski particularly whenskiing on icy steep hills. The width of the leaf spring can bedimensioned at each point in such a manner that the desired flexibilitycharacteristic exists, such as, for example, the spring can berelatively broad at the point located furthest toward the rear and wherethe sharpest curvature is present and can then taper inwardly towardsthe free end of the upper leg of the spring.

The present binding is particularly light in weight and can be easilyproduced if the pressure member is an elongation of the upper leg of theleaf spring and the pressure member and leaf spring are made as a singlecomponent. ln a different type of construction, the pressure member isconnected to the free end of the upper leg of the leaf spring via asuitable joint means.

The leaf spring can be selected in such a manner that the prestressdeveloped by the spring and with which the pressure member presses onthe rear edge of the heel of the ski boot or a metal fitting, will notbe dangerous to sensitive or inexperienced skiers, particularlychildren, during a fall. For skiers, whose mode or type of skiingrequires a higher prestress and whose physical condition permits suchhigher prestress, the prestress can also be augmented by connecting thetwo legs of the leaf spring at its open end or mouth with at least onetension spring. Depending upon the skier, tension springs of varyingstrength and/or diameter can be provided because the open end of theleaf spring provides sufficient space for permitting the attachment ofsuch tension springs. If the pressure member is connected with the upperleg of the leaf spring via a joint means, a tension spring can beattached adjacent each end of the axis of the joint means.

The surface with which the pressure member presses against the heel orthe metal heel fitting can be a substantially horizontal even plane inthe operating position and if the ski is to be removed when attached tothe ski boot with the present binding, it is easy to press the lower endof the pressure member rearwardly by hand until it slides off of theheel of the boot or the heel fitting whereby the foot is freed from thebinding. Dismounting is even simpler with a preferred embodiment of thepresent heel binding in which the free end of the upper leg of the leafspring is rolled around a hinge pin or spindle and is provided with alongitudinal slot or slit which receives the pressure member, with theslit defining a rest portion for the tip of the ski pole which may bepressed from the rear against an extension of the pressure memberprojecting upwardly above the hinge pin for releasing the lower end ofthe pressure member from the heel or heel fitting. With this type ofconstruction, the skier does not have to bend down if he desires to movethe ski since, when the leaf spring is constructed efficiently, itsupper leg is so broad that the rear end of the slot in which thepressure member is received can be sufiiciently widened for forming aneasily accessible point for receiving the tip of the ski pole. Thepivotal stress required for dismounting in regard to the swinging axiswhich lies lower than such accessible point can simply be produced bypressing the ski pole forward at its handle.

Since the pressure member, after mounting of the ski, is adapted to reston the heel or the heel fitting with a certain prestress, the mouth oropen end of the C-shaped left spring is to be somewhat widened duringsuch mounting. For example, this can be accomplished by holding theupper leg of the leaf spring and pulling the spring in an upwarddirection and the upper leg can be provided with a handle or the handlemay be at the upper end of the pressure member thereby making itpossible to adjust the binding. In order that the lower end of thepressure member after such end has reached the necessary height will"jump" forwardly as far as is required to press down the heel of theboot or the heel fitting, a smaller left spring may be provided at theunderside of the upper leg of the leaf spring and such smaller springwill press the pressure member in a forward direction. If the pressuremember is a part of the C-shaped leaf spring, the same action will occureven without an additional leaf spring.

According to a further embodiment of the invention, a bearing block isprovided at the lower leg of the C-shaped leaf spring in which islocated a two-armed lever swingable in a vertical longitudinal planewith the rearmost arm extending outwardly through an opening in the leafspring and which rear arm can be pressed downwardly by the tip of a skipole and the forwardmost arm is preferably considerably shorter andengages under the lower end of the pressure member which is thrustrearwardly by the heel when the ski boot is placed upon the ski andwhich is then lifted, by pressing down the rearmost arm into a positionin which the pressure member under the action of the forwardly pressingspring force attains its operative position.

In the present binding, the axis of the angular movement which isexecuted by the pressure member during release operation during a fallis not precisely defined. Even if the pressure member is connected via ajoint means with the C- shaped leaf spring, the pressure member is notonly swung around the axis of the joint means during the releaseoperation but the entire angular movement of the pressure memberincludes a component which results from the enlargement of the C-shapedleaf spring. Involved in this enlarging movement is at least the upperleg and the middle zone of the leaf spring and to ensure that the heelor the metal heel fitting is always released from the pressure memberduring a certain upward path of movement, independent from the pathdescribed by the upper arm of the leaf spring during enlargement, thepoint from which the pressure member extends away, it is advisable thatthe pressure member be provided with a nose or projection below ashoulder which presses on the upper rear edge of the heel or the metalheel fitting, which, if the heel moves upwardly after attaining anallowable maximum load, slides off from the rear edge of the heel orheel fitting and then presses the heel, after a certain upward path ofmovement, away from the shoulder.

In order that the pressure member is released from lateral guide forcesand for guaranteeing that the ski boot is always centered on the skiwhen mounting, the forward end of the lower leg of the C-shaped leafspring is displaced upwardly and is formed with two spaced-apart tinesor prongs which receive the heel fitting and the lower end of thepressure member therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in side elevation ofthe present heel safety binding for a ski,

FIG. 2 is a plan view partly in section of the binding illustrated inFIG. 1,

FIG. 3 is an elevational view viewed in the direction of arrow III inFIG. 2,

FIG. 4 is a view taken along line IV-IV, the view looking in thedirection of the arrows and in which the operative position isillustrated in dot-dash lines and the mounting position in full lines,and

FIG. 5 is a fragmentary view in elevation illustrating the release ofthebinding during a fall.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, it will beseen that a ski to which is to be attached a ski boot 12 is providedwith a baseplate 14 which may be secured thereto in any suitable fashionsuch as by means of screws (not illustrated). The guide plate 14 is bentupwardly and inwardly along its longitudinal edges so that it fits overthe lateral edges of a lower substantially horizontal leg 16 of aC-shaped leaf spring generally denoted 18. The leaf spring 18 is capableof adjustment in the longitudinal direction of the guide plate 14 andwhen in its properly adjusted position is maintained against accidentaldisplacement by means of a knurled head screw 20 whose free end entersone of a plurality of apertures 22 provided in the guide plate 14.

The leaf spring 18 is bend upwardly at its rear end or that end facingthe rear end of the ski 10 thus providing an upper leg 24 which extendsforwardly over the lower leg 16. As clearly as shown in FIG. 2, theupper leg 24 tapers inwardly towards its front or free end. The frontend is rolled as indicated at 26a for receiving a hinge pin or pintle 26and intermediate the ends of the rolled over portion 26a, the leg isprovided with a longitudinally extending slot 28 which is open at thefront thereof. A pressure member 30 is located on the hinge pin 26within the slot 28 and the lower end of the pressure member 30 isprovided with a shoulder 32 (FIG. 4) which, in the normal operatingposition of the binding, illustrated in FIG. 1 presses on a metal heelfitting 36 attached to heel 34 of the ski boot 12.

The forward end of the leg 16 of the spring 18 is displaced upwardly atapproximately a right angle and is bifurcated to provide two prongs ortines 38 (FIG. 2) between which the pressure member 30 extends and intowhich the heel fitting 36 engages in such a fashion that the latter isprevented from a lateral displacement. It should be mentioned that thetines or prongs 38 can be omitted if in some other manner there isprovided means for preventing lateral displacement of the heel 34 of theboot 12 such as, for example, by retaining clips fixed to the ski 10 orthe heel fitting 36 per se being bifurcated with the pressure memberengaging between the sidewalls of the cupshaped rear portion of the heelfitting and which are elongated in an upward direction similar to tinesor prongs.

The prestress with which the pressure member 30 presses against the heelfitting 36 and thus maintains the heel 34 of the ski boot against theupper surface of the ski 10 is effected partially by the leaf spring 18.The leaf spring 18 in its relaxed position is of the configurationillustrated in FIG. 4 and it is only upon mounting the ski to the skiboot 12 that the spring assumes the configuration illustrated in fulllines in FIG. 1 and in dot-dash lines in FIG. 4. The prestress developedby the leaf spring 18 is increased by two helical springs 40. It will benoted that each spring 40 is provided with a hook or the like at itslower end which engages an eye 42 while the upper end of the spring isdisposed in a groove provided adjacent the end of the hinge pin orspindle 26.

The eyes 42 constitute part of the bearing block generally denoted 44and at which is swingably positioned a lever 46 having front and reararms 48 and 52 respectively. It will be seen that the lever 46 isdisposed in the vertical longitudinal median plane of the ski and thebinding. A small leaf spring 50 is rivited or otherwise secured at itsrear end portion of the lower surface of the upper leg 24 of the spring18 and the forward end of the spring 50 presses upon the front arm 48 ofthe lever 46. The small spring 50 serves for maintaining the two armedlevers 46 in the angular position illustrated in FIG. 4 and at the sametime the spring 50 serves for pressing the lower end of the pressuremember 30 in a forward direction. The rear arm 52 of the lever 46projects rearwardly through a suitably formed opening 54 in the C-shapedleaf spring 18 and its rear portion is provided with a recess 52a whichcan receive the tip 56 ofa ski pole to enable pressure to be exerted onthe arm 52 (FIG. 4) for swinging the lever 46 against the action of theleaf spring 50. This particular arrangement serves the followingpurpose:

If, in order to mount the ski 10 to the ski boot 12, the ski bootillustrated in FIG. 4 is positioned on the ski in such a manner that theheel fitting 36 engages between the two tines 38, then the fittingpresses the lower end of the pressure member 30 rearwardly in theposition illustrated in FIG. 4. In this position, a nose or projection58 provided at the lower end of the pressure member 30 and extendingdownwardly is located immediately above the front arm 48 of the lever46. If the rear end 52 of the lever 46 is pressed downwardly by the tipof the ski pole, the front arm 48 of the lever 46 acts upon the pressuremember 40 during its upwardly directed swing until the shoulder 32 ofthe pressure member attains the height of the upper edge of thecup-shaped rear portion of the heel fitting 36. From this position, theleaf spring 50 presses the pressure member 30 into the operativeposition illustrated by FIG. 1 by full lines and in FIG. 4 by dotdashlines. The rear arm 52 of the lever 46 is approximately three times thelength of the front arm 48 and consequently the force with which the arm52 must be pressed downwardly merely amounts to one third of theprestress with which the pressure member 30 presses upon the heelfitting 36 in the operative position.

The nose or projection 58 at the lower end of the pressure member 30serves yet another purpose namely the purpose of increasing the safetyof the binding. If, during a forward fall, the inertia which induces theskier to fall forwardly becomes so great that the heel 34 of the skiboot is drawn upwardly with a force which is greater than the prestressof the pressure member 30, the two helical springs 40 and the opening ofthe leaf spring are enlarged. The hinge pin or spindle 26 of thepressure member 30 moves upwardly and at the same time somewhatrearwardly with the pressure member 30 executing a swinging motionaround the axis. During this motion, the nose or projection 58 comesinto contact with the rear wall of the heel fitting 36 and is in cammingengagement therewith. After a certain upward movement of the heel 34,the position of the pressure member in relation to the heel fitting 36is obtained as is illustrated in H0. 5. In this position, the nose orprojection functions as a release and ensures that the fitting 36 isindeed released from the shoulder 32 of the pressure member 30. In thisfashion, the upward path of movement which must be covered by the heel34 until it is completely released by the binding is predeterminedsufficiently precisely for avoiding injuries to the skier by possibledelayed release of the binding even though the adjustment of the springs18 and 40 was correct.

If a skiing movement is terminated by a normal dismounting of the skisinstead of a fall as above-described, the tip 56 of a ski pole (FIG. 2)can be inserted into the rear portion of the slot 28 which is afunnellike component 60 and thus exert a forwardly directed pressureonto portion 62 of the pressure member 30 which extends upwardly abovethe hinge pin or spindle 26. As a consequence, the lower end of thepressure member is swung rearwardly and the shoulder 32 slides off theheel fitting 36.

This invention is not to be limited to the embodiment shown in thedrawings but changes or modifications may be made therein so long assuch changes or modifications cause no material departure from thespirit and scope of the appended claims.

I claim:

1. A heel safety binding comprising a pressure member mounted forswinging movement in a vertical longitudinal plane on a ski, saidpressure member extending downwardly and forwardly for pressing on therear edge or heel fitting of a ski boot under a resilient prestress, andupon attaining an admissible maximum load executing an upward angularmovement against the resilient prestress in the vertical longitudinalplane and during which the heel of the ski boot is released from thepressure member after a predetermined point in the upward angular path.the improvement comprising a C-shaped leaf spring having an upper leg, alower leg, a closed end, and an open end, said lower leg being mountedon the ski with said closed end facing the rear of the ski, and meansoperatively connecting the upper portions of the pressure member to theupper leg of the leaf spring The heel safety blll mg as claimed in claim1 in which said pressure member is connected by means of a hinge pinwith a free end of said upper leg.

3. The heel safety binding as claimed in claim 1 in which said upper andlower legs of the leaf spring are connected adjacent the open end by atleast one helical spring.

4. The heel safety binding as claimed in claim 2 in which a helicalspring is connected to said hinge pin adjacent each end thereof and tosaid lower leg of said leaf spring.

5. The heel safety binding as claimed in claim 2 in which said hinge pinextends through a rolled portion of the free end of said upper leg andsaid upper leg being provided with a longitudinal slot for receivingsaid pressure member, said slot merging with a connecting pointrearwardly of said hinge pin for receiving the top of a ski pole forpressing from behind an extension of the pressure member projectingupwardly above the hinge pin for releasing the lower end of the pressuremember from the rear edge or heel fitting of the ski boot.

6. The heel safety binding as claimed in claim 2 including a small leafspring connected at one end of the undersurface of the upper leg of saidC-shaped leaf spring and the opposite end of said small leaf springpressing said pressure member forwardly.

7. The heel safety binding as claimed in claim 1 including a bearingblock provided on the lower leg of said C-shaped leaf spring, atwo-armed lever mounted on said bearing block for swinging movement inthe vertical longitudinal plane, the rear arm of said lever extendingthrough an opening in the closed end of said leaf spring capable ofbeing pressed downwardly by the tip of a ski pole, the front arm ofsaid-lever being of lesser length than the rear arm and engaging underthe lower end of said pressure member which is pressed rearwardly bypositioning a ski boot onto the ski thereby raising the pressure memberinto a position from which it will independently arrive at its operativeposition under the action of a spring force which presses the sameforwardly.

8. The heel safety binding as claimed in claim 1 in which the forwardend of said lower leg of said C-shaped leaf spring is directed upwardlyat an angle to said leg, said upwardly directed portion being bifurcatedto provide two spaced tines which receive the heel fitting and the lowerend of the pressure member.

9. The heel safety binding as claimed in claim 1 in which the lower legof said C-shaped leaf spring is mounted on a baseplate secured to theski so as to be adjustable in the longitudinal direction of the ski.

10. The heel safety binding as claimed in claim 1 wherein said pressuremember at its downward end pressing on the rear edge or heel fitting ofthe ski boot, comprises: a shoulder formation engaging said rear edge orheel fitting in normal skiing operation; and an extension which partlyforms said shoulder, the extension being in the form of a rounded nosewhich comes into camming engagement with the rear face of the rear edgeor heel fitting of the ski boot so as to assist in the release of theboot from the safety binding when the heel of the boot is drawn upwardlywith a force greater than a predetermined limit.

1. A heel safety binding comprising a pressure member mounted forswinging movement in a vertical longitudinal plane on a ski, saidpressure member extending downwardly and forwardly for pressing on therear edge or heel fitting of a ski boot under a resilient prestress, andupon attaining an admissible maximum load executing an upward angularmovement against the resilient prestress in the vertical longitudinalplane and during which the heel of the ski boot is released from thepressure member after a predetermined point in the upward angular path,the improvement comprising a C-shaped leaf spring having an upper leg, alower leg, a closed end, and an open end, said lower leg being mountedon the ski with said closed end facing the rear of the ski, and meansoperatively connecting the upper portions of the pressure member to theupper leg of the leaf spring.
 2. The heel safety binding as claimed inclaim 1 in which said pressure member is connected by means of a hingepin with a free end of said upper leg.
 3. The heel safety binding asclaimed in claim 1 in which said upper and lower legs of the leaf springare connected adjacent the open end by at least one helical spring. 4.The heel safety binding as claimed in claim 2 in which a helical springis connected to said hinge pin adjacent each end thereof and to saidlower leg of said leaf spring.
 5. The heel safety binding as claimed inclaim 2 in which said hinge pin extends through a rolled portion of thefree end of said upper leg and said upper leg being provided with alongitudinal slot for receiving said pressure member, said slot mergingwith a connecting point rearwardly of said hinge pin for receiving thetip of a ski pole for pressing from behind an extension of the pressuremember projecting upwardly above the hinge pin for releasing the lowerend of the pressure member from the rear edge or heel fitting of the skiboot.
 6. The heel safety binding as claimed in claim 2 including a smallleaf spring connected at one end of the undersurface of the upper leg ofsaid C-shaped leaf spring and the opposite end of said small leaf springpressing said pressure member forwardly.
 7. The heel safety binding asclaimed in claim 1, including a bearing block provided on the lower legof said C-shaped leaf spring, a two-armed lever mounted on said bearingblock for swinging movement in the vertical longitudinal plane, the reararm of said leveR extending through an opening in the closed end of saidleaf spring capable of being pressed downwardly by the tip of a skipole, the front arm of said lever being of lesser length than the reararm and engaging under the lower end of said pressure member which ispressed rearwardly by positioning a ski boot onto the ski therebyraising the pressure member into a position from which it willindependently arrive at its operative position under the action of aspring force which presses the same forwardly.
 8. The heel safetybinding as claimed in claim 1 in which the forward end of said lower legof said C-shaped leaf spring is directed upwardly at an angle to saidleg, said upwardly directed portion being bifurcated to provide twospaced tines which receive the heel fitting and the lower end of thepressure member.
 9. The heel safety binding as claimed in claim 1 inwhich the lower leg of said C-shaped leaf spring is mounted on abaseplate secured to the ski so as to be adjustable in the longitudinaldirection of the ski.
 10. The heel safety binding as claimed in claim 1wherein said pressure member at its downward end pressing on the rearedge or heel fitting of the ski boot, comprises: a shoulder formationengaging said rear edge or heel fitting in normal skiing operation; andan extension which partly forms said shoulder, the extension being inthe form of a rounded nose which comes into camming engagement with therear face of the rear edge or heel fitting of the ski boot so as toassist in the release of the boot from the safety binding when the heelof the boot is drawn upwardly with a force greater than a predeterminedlimit.